Some results of the Prospective Urban Rural Epidemiology (PURE) study published today in the Lancet seem to refute the long-held U.S. nutritional federal guidelines that have advised a reduced fat diet.
Among 135,000 adults aged 35-70 from 18 different countries, higher saturated fat intake was associated with a LOWER risk of stroke of about 20% (for a 95% confidence interval of 0.64 to 0.98). Contrary to popular belief, saturated and non-saturated fat had about the same health effects.
Higher carbohydrate intake was associated with an increased hazard ratio of about 28% with only a 2.5% probability that this number is actually less than 12%.
In plain English: eat grilled meats, add butter, add cream, and trash candies.
This study adds to the long stream of similar nutritional results that have been coming out slowly but steadily from academia in the past 10 or so years. In addition to causing heart attacks and diabetes, it is increasingly likely that carbohydrates, especially fast sugars, also cause a statistically significant number of cancers.
Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study
Dr Mahshid Dehghan, PhD, Andrew Mente, PhD, Xiaohe Zhang, MSc, Sumathi Swaminathan, PhD, Prof Wei Li, PhD, Prof Viswanathan Mohan, MD, Romaina Iqbal, PhD, Prof Rajesh Kumar, MD, Edelweiss Wentzel-Viljoen, PhD, Prof Annika Rosengren, MD, Leela Itty Amma, MD, Prof Alvaro Avezum, MD, Jephat Chifamba, DPhil, Rafael Diaz, MD, Rasha Khatib, PhD, Prof Scott Lear, PhD, Prof Patricio Lopez-Jaramillo, MD, Xiaoyun Liu, PhD, Prof Rajeev Gupta, MD, Noushin Mohammadifard, PhD, Nan Gao, BSc, Aytekin Oguz, MD, Anis Safura Ramli, MD, Pamela Seron, PhD, Yi Sun, MSc, Prof Andrzej Szuba, MD, Lungiswa Tsolekile, MPH, Prof Andreas Wielgosz, MD, Rita Yusuf, PhD, Afzal Hussein Yusufali, MD, Prof Koon K Teo, MD, Sumathy Rangarajan, MSc, Gilles Dagenais, MD, Shrikant I Bangdiwala, PhD, Shofiqul Islam, MSc, Prof Sonia S Anand, Prof Salim Yusuf, DPhil
Published: 29 August 2017
The relationship between macronutrients and cardiovascular disease and mortality is controversial. Most available data are from European and North American populations where nutrition excess is more likely, so their applicability to other populations is unclear.
The Prospective Urban Rural Epidemiology (PURE) study is a large, epidemiological cohort study of individuals aged 35–70 years (enrolled between Jan 1, 2003, and March 31, 2013) in 18 countries with a median follow-up of 7·4 years (IQR 5·3–9·3). Dietary intake of 135 335 individuals was recorded using validated food frequency questionnaires. The primary outcomes were total mortality and major cardiovascular events (fatal cardiovascular disease, non-fatal myocardial infarction, stroke, and heart failure). Secondary outcomes were all myocardial infarctions, stroke, cardiovascular disease mortality, and noncardiovascular disease mortality. Participants were categorized into quintiles of nutrient intake (carbohydrate, fats, and protein) based on percentage of energy provided by nutrients. We assessed the associations between consumption of carbohydrate, total fat, and each type of fat with cardiovascular disease and total mortality. We calculated hazard ratios (HRs) using a multivariable Cox frailty model with random intercepts to account for center clustering.
During follow-up, we documented 5796 deaths and 4784 major cardiovascular disease events. Higher carbohydrate intake was associated with an increased risk of total mortality (highest [quintile 5] vs lowest quintile [quintile 1] category, HR 1·28 [95% CI 1·12–1·46], ptrend=0·0001) but not with the risk of cardiovascular disease or cardiovascular disease mortality. Intake of total fat and each type of fat was associated with lower risk of total mortality (quintile 5 vs quintile 1, total fat: HR 0·77 [95% CI 0·67–0·87], ptrend<0·0001; saturated fat, HR 0·86 [0·76–0·99], ptrend=0·0088; monounsaturated fat: HR 0·81 [0·71–0·92], ptrend<0·0001; and polyunsaturated fat: HR 0·80 [0·71–0·89], ptrend<0·0001). Higher saturated fat intake was associated with lower risk of stroke (quintile 5 vs quintile 1, HR 0·79 [95% CI 0·64–0·98], ptrend=0·0498). Total fat and saturated and unsaturated fats were not significantly associated with risk of myocardial infarction or cardiovascular disease mortality.
High carbohydrate intake was associated with higher risk of total mortality, whereas total fat and individual types of fat were related to lower total mortality. Total fat and types of fat were not associated with cardiovascular disease, myocardial infarction, or cardiovascular disease mortality, whereas saturated fat had an inverse association with stroke. Global dietary guidelines should be reconsidered in light of these findings.